The EFSA Journal (2006) 392, 1-6

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1 The EFSA Journal (2006) 392, 1-6 Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food On a request from the Commission related to SUMMARY Magnesium Potassium Citrate as a source of magnesium and potassium in food for particular nutritional uses, food supplements and foods intended for the general population Question n EFSA-Q Adopted on 27 September 2006 The Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC Panel) has been asked to evaluate the safety and bioavailability of magnesium potassium citrate as a source of magnesium and potassium when added for nutritional purposes in foods for particular uses in food supplements and in foods intended for the general population. The present opinion deals only with the safety and bioavailability of a particular source of magnesium and potassium, magnesium potassium citrate. The safety of magnesium and potassium itself, in terms of the amounts that may be consumed, is outside the remit of this Panel. The safety evaluation of magnesium potassium citrate as a source for magnesium and potassium in food supplements is based on the safety evaluations of the individual substances, citric acid, potassium citrate and magnesium citrate. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1973 and the EC Scientific Committee on Food (SCF) in 1990 evaluated the individual substances as food additives and established an ADI not specified for citrate and for the cations potassium and magnesium. Citric acid has a well-established role as an intermediate metabolite in the tricarboxylic acid cycle. Citrates occur in many foods and are normal metabolites in the body and are therefore considered as of no safety concern. The Panel concluded that the use of magnesium potassium citrate as a source for magnesium and potassium in food for particular nutritional uses, food supplements and foods intended for the general population is of no safety concern. Regarding bioavailability, data in the literature show that potassium magnesium citrate provides an equivalent potassium bioavailability to that of potassium citrate and potassium chloride, and a comparable magnesium bioavailability to that of magnesium citrate. The specifications of magnesium potassium citrate as commercialised should comply with the specifications for citric acid and its salts used as food additives.

2 Magnesium Potassium Citrate The EFSA Journal (2006) 392, p. 2 of 6 KEY WORDS Magnesium potassium citrate, 2-Hydroxy-1,2,3,-propane tricarboxylic acid Magnesium (2:1) Potassium(2:2) salt, Mg K Citrate, CAS Nr , food supplements. BACKGROUND The European Community legislation lists substances that may be used for nutritional purposes in certain categories of foods as sources of certain nutrients. This application is a request for the inclusion of magnesium potassium citrate in Annex of: Commission Directive 2001/15/EC of 15 February 2001 on substances that may be added for specific nutritional purposes in foods for particular nutritional uses (EC, 2001). Directive 2002/46/EC of the European Parliament and of the Council on the approximation of the laws of the Member States relating to food supplements (EC, 2002). In addition, there is a Commission proposal for a regulation on the addition of vitamins and minerals and certain other substances to foods. TERMS OF REFERENCE In accordance with Article 29 (1) (a) of Regulation (EC) No 178/2002, the European Commission asks the European Food Safety Authority (EFSA) to provide a scientific opinion, based on its considerations of the safety and bioavailability of the substance magnesium potassium citrate when added for nutritional purposes in foods for particular uses and foods (including food supplements) intended for the general population. ASSESSMENT The present opinion deals only with the safety and bioavailability of magnesium potassium citrate as a source of magnesium and potassium intended for the general population, to be used in food supplements and in foods for particular nutritional uses. The safety of magnesium and potassium itself, in terms of the amounts that may be consumed, is outside the remit of this Panel. Chemistry Magnesium potassium citrate is a mixed salt of magnesium and potassium with citric acid, a substance with as chemical name [2-Hydroxy-1, 2, 3,-propane tricarboxylic acid Magnesium (2:1) Potassium (2:2) salt], chemical formula K 4 Mg (C 6 H 5 O 7 ) 2. The

3 Magnesium Potassium Citrate The EFSA Journal (2006) 392, p. 3 of 6 percentage weight of magnesium, potassium and citrate in magnesium potassium citrate are therefore respectively 4.3%, 28% and 67.7%. Molecular mass: g/mol; CAS registration number: ; White crystalline powder, stable for several months at room temperature and at 40 C; Freely soluble in water (gives a ph 5 7) and diluted HCl; insoluble in methanol. Specifications According to the petitioner magnesium potassium citrate contains, on a dried basis, not less than 26% potassium and not less than 4% magnesium. The calculated citric acid content is not less than 68%. The lead and arsenic contents are below 1 mg/kg. In a sieve test, not less than 90% passes at 40 mesh and not less than 75% passes at 80 mesh. The loss on drying is not more than 6%. Manufacturing process According to the petitioner citric acid is added to demineralised water under stirring. Then, calculated quantities of magnesium oxide are added followed by the addition of calculated quantities of potassium carbonate to adjust the ph to The reaction mixture is further stirred and the resulting precipitate is removed and dried. Methods of analysis in food Not applicable. Reaction and fate in foods According to the petitioner no reactions are expected to occur under normal processing conditions. The petitioner provides data demonstrating that magnesium potassium citrate is stable for up to six months at 40 C and 75% relative humidity and up to sixty months at 25 C and 60% relative humidity. Exposure No specific data were provided by the petitioner. The potential exposure to citric acid was calculated based on the hypothesis that addition of magnesium potassium citrate in food would be such as not to exceed either 250 mg per day of magnesium or 3 g per day of potassium. Based on the percentage weight of magnesium (28%) in the substance, the intake of magnesium potassium citrate should be less than 893 mg in order to limit the additional intake of magnesium to less than 250 mg per day. In these conditions, based on the percentage weight of potassium (4.3%), the additional intake of potassium would also be far less than its safety limit of 3 g. The additional daily intake of citric acid deriving from the addition of magnesium potassium citrate within the safety limits established for potassium and magnesium may therefore be up to around 600 mg of citric acid, considering that citric acid represents 67.7% of weight of the substance.

4 Magnesium Potassium Citrate The EFSA Journal (2006) 392, p. 4 of 6 Existing authorisations and evaluations In the EU, citric acid (E330) and its potassium salt (E332) are permitted food additives (EC, 2006). The magnesium salts of citric acid and potassium citrate are also permitted substances in all foods for particular nutritional uses (EC, 2001). Biological and toxicological data Bioavailability of magnesium and potassium from their Mg K citrate source Data in the literature show that potassium magnesium citrate provides an equivalent potassium bioavailability to that of potassium citrate and potassium chloride, and a comparable magnesium bioavailability to that of magnesium citrate (Koenig et al., 1991). Toxicological data The JECFA evaluated citric acid and its salts as food additives in 1973 and concluded that due to the fact that these substances are natural constituents of the diet and that the intake from food additives is likely to be insignificant compared to the intake from natural sources there is no need for specific toxicity data. JECFA established an acceptable daily intake (ADI) not specified for citrate (JECFA, 1974). The SCF evaluated citric acid and its potassium and magnesium salts in 1990 and established an ADI not specified for the cations potassium and magnesium. The SCF however, emphasized that no safety problems are likely to arise, provided the contributions from food intake do not disturb the homeostasis mechanisms controlling the electrolyte balance of the body. For magnesium, large single doses taken in bulk are known to produce diarrhoea particularly in children, and should be avoided (SCF, 1991). In evaluating the acceptability of citrate the SCF emphasized that citrate has a wellestablished role as an intermediate metabolite in the citric acid cycle and as a natural component of food. The Committee agreed with the group ADI not specified established by JECFA (SCF, 1991). CONCLUSION From data in the literature it can be concluded that magnesium and potassium are bioavailable from magnesium potassium citrate. Their bioavailability is expected to be equivalent to their bioavailability from magnesium citrate and potassium citrate respectively. The safety evaluation of magnesium potassium citrate as a source for magnesium and potassium in food for particular nutritional uses and foods (including. food supplements) intended for the general population is based on the safety evaluations of the individual substances, citric acid, potassium citrate and magnesium citrate. The JECFA in 1973 and the SCF in 1990 evaluated the individual substances as food

5 Magnesium Potassium Citrate The EFSA Journal (2006) 392, p. 5 of 6 additives and established an ADI not specified for citrate and for the cations potassium and magnesium. If the addition of magnesium potassium citrate to food is such that the safety limits established for potassium and magnesium are not exceeded, the additional intake of citric would up to around 600 mg which is of no safety concern. Citric acid has a well-established role as an intermediate metabolite in the tricarboxylic acid cycle. Citrates occur in many foods and are normal metabolites in the body and are therefore, considered as of no safety concern. The Panel concluded that the use of magnesium potassium citrate as a source of magnesium and potassium in foods for particular nutritional uses and foods (including food supplements) intended for the general population is of no safety concern. The Panel emphasises that the specifications of magnesium potassium citrate as commercialised should comply with the specifications for citric acid and its salts used as food additives. DOCUMENTATION PROVIDED TO EFSA Dossier on magnesium potassium citrate, Application for derogation submitted by Sami Labs Limited, Bangalore, India (July, 2005) REFERENCES EC (2001). Commission Directive 2001/15/EC of 15 February 2001 on substances that may be added for specific nutritional purposes in foods for particular nutritional uses. Official Journal of the European Communities, L52, , pg EC (2002) Directive 2002/46/EC of the European Parliament and of the Council on the approximation of the laws of the Member States relating to food supplements. Official Journal of the European Communities, L183, , pg EC (2006) European Parliament and Council Directive 95/2/EC of 20 February 1995, on food additives other than colours and sweeteners, amended by Directives 96/85/EC, 98/72/EC, 2001/5/EC, 2003/52/EC, 2003/114/EC and Directive 2006/52/EC, Official Journal of the European Communities, L204, , pg EFSA, European Food Safety Authority (2005). Opinion of the NDA Panel related to the Tolerable Upper Intake Level of Potassium. JECFA (1974). Toxicological evaluation of certain food additives with a review of general principles and specifications (Seventeenth report of the Joint FAO/WHO Expert Committee on Food Additives). FAO Nutrition Meetings Series, No 53, 1974; WHO Technical Report Series, No. 539, 1974, and corrigendum.

6 Magnesium Potassium Citrate The EFSA Journal (2006) 392, p. 6 of 6 Koenig K, Padalino P, Alexandrides G, Pak CY. (1991). Bioavailability of potassium and magnesium, and citraturic response from potassium magnesium citrate. J. Urol. 145(2): SCF, EC Scientific Committee on Food (2001). Opinion of the Scientific Committee on Food on the Tolerable Upper Intake Level of Magnesium (expressed on 26 September 2001). SCF, EC Scientific Committee for Food (1991). Reports from the Scientific Committee on Food (25 th Series) Opinion expressed in May Food-Science and Techniques 25. SCF, EC Scientific Committee for Food (1993). Nutrient and energy intakes for the European Community. Reports of the Scientific Committee for Food (Thirty-first series). European Commission, Luxembourg. AFC Scientific Panel Members Fernando Aguilar, Herman Autrup, Sue Barlow, Laurence Castle, Riccardo Crebelli, Wolfgang Dekant, Karl-Heinz Engel, Natalie Gontard, David Gott, Sandro Grilli, Rainer Gürtler, John Chr. Larsen, Catherine Leclercq, Jean-Charles Leblanc, F. Xavier Malcata, Wim Mennes, Maria Rosaria Milana, Iona Pratt, Ivonne Rietjens, Paul Tobback, Fidel Toldrá.